Field measurement of survival rates of juvenile Acanthaster piano, techniques and preliminary results

Techniques are described which enable measurement of mortality rates of post-metamorphic Acanthasterplanci (L.) as small as 0.5 mm in the field.Results indicate that mortality rates at this time are significant, viz.6.49 % d-' for l-mo-old starfish (mean size = 1.1 mm) decreasing to 1.24 and 0.45 % d-' for 4-(2.7 mm) and 7-mo-old (5.5 mm) starfish respectively.Experiments involving exclusion of predators indicated that the major source of mortality was predation by epibenthic fauna.Results also show that in the presence of adequate food supply juvenile A. planci move very little.This suggests that survival will be enhanced by settling in areas where predation will be minimal.